Claim · model-written summary
Usually three micropylar megaspores degenerate and the chalazal one functions, with one reversed instance.
- Taxon
- Dionaea Muscipula
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Dionaea muscipulat0 - Outcome
- three micropylar potential megaspores degenerate and the chalazal one functionse0
Not reportedMaterialGeneCompoundOrgan / stageInteractorInteractor roleSecond interactorSecond interactor roleTreatmentComparatorSettingDirectionValueQualifier
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
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Verbatim
e0“Usually, as in other angiosperms, the three micropylar potential megaspores degenerate and the chalazal one functions. In one instance the three basal spores degenerated and the micropylar one functioned.”
t0“Dionaea Muscipula”
Title
Development of Dionaea Muscipula. I. Flower and Seed
Cornelia Marschall Smith Botanical Gazette 1929. doi:10.1086/333957
Other claims from this paper (18)
- Observation The terminal bud forms a scape bearing two to fourteen flowers.
- Observation Young flower vascular bundles support stamen development in alternipetalous and epipetalous whorls.
- Observation When more than ten stamens develop, division of an epipetalous stamen vascular bundle supplies additional stamens.
- Observation Each stamen develops four microsporangia in the usual manner.
- Observation Forty-eight to sixty microsporocytes develop in each sporangium and have discernible prochromosomes in early prophase.
- Observation Each of four nuclei after the second meiotic division has fifteen haploid chromosomes.
- Observation Mature pollen grains remain in tetrads and each has six to eight large germinating pores.
- Observation The ovary has five carpels and produces numerous anatropous ovules on a basal placenta.
- Observation The second integument outer layer forms a columnar outer seed coat.
- Observation The inner integument forms a lid pushed off at germination.
- Observation The single vascular strand to the chalazal end of each ovule does not twist.
- Observation The nucellar outer cell layer expands radially around a central strand of elongated cells.
- Observation Division of one hypodermal archesporial cell forms two or three parietal layers above the embryo sac.
- Observation Usually one megaspore mother cell forms two then four potential megaspores, with daughter divisions not necessarily simultaneous.
- Observation Three divisions of the functional megaspore produce an embryo sac with egg apparatus, polar nuclei, and antipodals.
- Observation The primary endosperm nucleus usually divides several times before the fertilized egg forms the embryo and suspensor.
- Observation Growing endosperm displaces all nucellar tissue by the end of free nuclear division.
- Observation The mature seed has a basal embryo with two cotyledons and a short radicle surrounded by cellular endosperm.